package lihao.Test13;

public class Test {
    public static void main(String[] args) {
        BlackBird black = new BlackBird("black");
        GreenBird green = new GreenBird("green");
        RedBird red = new RedBird("red");
        YellowBird yellow = new YellowBird("yellow");
        black.voice();
        green.voice();
        red.voice();
        yellow.voice();
    }
}
